Will there be a broadcast reminder when the train arrives? What if I sit on it? Do the people in the carriage get on and off at the same place?

There will be a broadcast reminder when the train arrives at the station, and the administrator of each carriage will also remind it;

If the train did, it would be a mistake to take the station. You can find the conductor before you get off the bus and ask him to issue an error certificate. After getting off the bus, you don't have to buy a return ticket if you find the person on duty at the station with the voucher. If you have already got off the bus, you can also find the station attendant. Under normal circumstances, the station will help passengers return to their destination as long as they explain that they have made a mistake and have not acted intentionally.

People in a car don't get on and off at the same place, and it's not necessarily where people in a car get on and off.